261824121 has 12 divisors (see below), whose sum is σ = 407282148. Its totient is φ = 161122464.

The previous prime is 261824117. The next prime is 261824149. The reversal of 261824121 is 121428162.

261824121 is a `hidden beast` number, since 2 + 618 + 2 + 41 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 12531600 + 249292521 = 3540^2 + 15789^2 .

It is not a de Polignac number, because 261824121 - 2² = 261824117 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261824621) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1118790 + ... + 1119023.

It is an arithmetic number, because the mean of its divisors is an integer number (33940179).

Almost surely, 2^261824121 is an apocalyptic number.

It is an amenable number.

261824121 is a deficient number, since it is larger than the sum of its proper divisors (145458027).

261824121 is a wasteful number, since it uses less digits than its factorization.

261824121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2237832 (or 2237829 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 261824121 is about 16180.9802237071. The cubic root of 261824121 is about 639.7395758479.

It can be divided in two parts, 26182 and 4121, that added together give a palindrome (30303).

The spelling of 261824121 in words is "two hundred sixty-one million, eight hundred twenty-four thousand, one hundred twenty-one".